The present invention relates, in general, to the field of suspended monorails, also known as hanging trains or suspended coaches.
Hanging trains are used to carry passengers, and in some cases, freight. They utilize a fixed guide way from which passenger coaches or containers are suspended. There is most commonly an electric motor powering a bogie, which incorporates drive wheels that are used to propel the coaches along the guide way. The motors and wheels are integrated into the bogies, which travel along with the coaches. The electricity used to power the motors and wheels is generally made available to the motors through a system of bus-bars and shoes or brushes. In systems from the late nineteenth and early twentieth centuries, the drive wheels and electric motors were exposed to the weather, and the drive wheels rode on a single iron rail. In later systems, the bogies were enclosed within the guide ways, with the wheels driving on a set of internal guide way tracks.
The earliest operating suspended monorail that is still in service today was designed by Carl Eugen Langen for use in Wuppertal, Germany (1901). This German system utilized a single rail, similar to those found on conventional rail lines, and a set of wheels that ride on the single overhead rail. The passenger coaches hang, balanced directly beneath the overhead rail. A set of electric motors is connected to the wheels to propel the vehicles. This system currently carries about 75,000 riders per day on a dual-track, bidirectional route up and down the Wuppertal valley.
During the mid-twentieth century, a new approach was developed in which the bogies are concealed within a fixed guide way structure. The guide way is a rectilinear, hollow structural member incorporating a continuous slot opening in the bottom side. The electrically-powered bogies are completely contained within the guide way, except for a hinge affixed to the bogies aligned with, and accessible through, the slot in the bottom of the guide way. Passenger coaches are fastened to the hinges, thus allowing the coaches to swing in response to gravity and centrifugal forces acting on the coaches as the coaches travel around curved portions of the guide way. The bogies ride on two rails, or tracks: one on each side of the slot in the guide way structure.
For these systems, electrical bus-bars and connecting electrical shoes carry electrical power to the bogies. Motors use the electrical power to propel the coaches, and to provide lighting and door actuation on board the coaches.